An electronic trading system provides a central market place where both buyers and sellers (often referred to as traders) can buy/sell their preferred derivative instrument. Traders connect to the electronic trading system via an application program interface (API) which interprets messages from their own trading computers. Although all trading is executed electronically, the preferred trading strategies can vary greatly from one trader to another.
Electronic trading systems support a number of common order types that can be submitted into the market. Users of electronic trading systems incorporate these various orders into their trading strategies. Three types of most common orders are: limit orders, stop orders, and market orders (also referred to as “at market orders”). First, a limit order is an order to buy/sell a set number of contracts at a pre-determined price. A stop order is commonly understood to be an order to buy or sell a set number of contracts at the prevailing market price if and when a specified price is reached. Practically, the buyer or seller takes a view that if a certain price in the market was to trade or be broken (i.e., go beyond) then this would strongly indicate price direction.
The stop order was originally devised to protect against a loss (a stop loss) where a trader has a position and wants to reverse the position quickly. Over time the stop order has evolved to not only limit loss but to trade in a direction to make and/or take profits. Finally, a market order is an order to buy/sell a set number of contracts at the prevailing market price until the specified quantity has been met or the order cancelled. A market order has no price at which to trade just a quantity of lots. Specifically, the market order in layman's terms corresponds to “I don't care what price I trade at as long as I trade.”